The 3rd person perspective assumes the existence (or at least possibility) of some observer X who knows everything and can observe how events evolve across all branches.
However, this idea assumes that this observer X will be singular and unique, will continue to exist as one entity, and will linearly collect information about unfolding events.
These assumptions clearly relate to ideas of personal identity and copying: it is assumed that X exists continuously in time and cannot be copied. Otherwise, there would be several 3rd person perspectives with different observations.
This concept can be better understood through real physical experiments: an experiment can only be performed if the experimenter exists continuously and is not replaced by another experimenter midway through.
By “3rd person perspective” I mean considering the world itself, there is no actual third person needed for it. It’s the same framing as used by a physicist when talking about the early stages of the universe when humans were not yet around, or when talking about a universe with alternative laws of physics, or when talking about a small system that doesn’t include any humans as its part. Or when a mathematician talks about a curve on a plane.
Knowing absolutely everything is not necessary to know the relevant things, and in this case we know all the people at all times, and the states of their minds, their remembered experiences and possible reasoning they might perform based on those experiences. Observations take time and cognition to process, they should always be considered from slightly in the future relative to when raw data enters a mind. So it’s misleading to talk about a person that will experience an observation shortly, and what that experience entails, the clearer situation is looking at a person who has already experienced that observation a bit in the past and can now think about it. When a copied person looks back at their memories, or a person about to be copied considers what’s about to happen, the “experience” of being copied is nowhere to be found, there is only the observation of the new situation that the future copies find themselves in, and that has nothing to do with the splitting into multiple copies of the person from the past.
The 3rd person perspective assumes the existence (or at least possibility) of some observer X who knows everything and can observe how events evolve across all branches.
However, this idea assumes that this observer X will be singular and unique, will continue to exist as one entity, and will linearly collect information about unfolding events.
These assumptions clearly relate to ideas of personal identity and copying: it is assumed that X exists continuously in time and cannot be copied. Otherwise, there would be several 3rd person perspectives with different observations.
This concept can be better understood through real physical experiments: an experiment can only be performed if the experimenter exists continuously and is not replaced by another experimenter midway through.
By “3rd person perspective” I mean considering the world itself, there is no actual third person needed for it. It’s the same framing as used by a physicist when talking about the early stages of the universe when humans were not yet around, or when talking about a universe with alternative laws of physics, or when talking about a small system that doesn’t include any humans as its part. Or when a mathematician talks about a curve on a plane.
Knowing absolutely everything is not necessary to know the relevant things, and in this case we know all the people at all times, and the states of their minds, their remembered experiences and possible reasoning they might perform based on those experiences. Observations take time and cognition to process, they should always be considered from slightly in the future relative to when raw data enters a mind. So it’s misleading to talk about a person that will experience an observation shortly, and what that experience entails, the clearer situation is looking at a person who has already experienced that observation a bit in the past and can now think about it. When a copied person looks back at their memories, or a person about to be copied considers what’s about to happen, the “experience” of being copied is nowhere to be found, there is only the observation of the new situation that the future copies find themselves in, and that has nothing to do with the splitting into multiple copies of the person from the past.